关键词: 尾叶桉, 树皮厚度, 无性系, 生长性状

Abstract: In order to reveal the response mechanism of growth and bark thickness for Eucalyptus urophylla under different water and fertilizer gradients, 31 clones treated with nine combination of water and nutrients were used as experimental materials. After 18 months of artificial control of water and nutrient, the height, ground diameter, height under branch, 1/4 diameter, 2/4 diameter, 3/4 diameter and bark thickness were measured. The co-efficient of variation, Duncan multiple comparison and principal components were analyzed, and excellent clones were selected. The results showed that the growth and bark thickness traits of E. urophylla clones had great variation. Among them, the variation coefficient of height under branch and ground diameter was 50.78% and 12.46%, respectively, which suggested that analyzed traits had extensive variation with rich genetic diversity. There were significant differences in height, ground diameter, bark thickness, 1/4 diameter, 2/4 diameter and 3/4 diameter of E. urophylla clones under different water and fertilizer treatments. All clones performed better under 32 and 33 treatments. The 6 traits could be integrated into 3 principal components, and the cumulative contribution rate of the first 3 principal components was 84%. According to the genotype values of height, bark thickness and ground diameter, the best clones were 30, 7, 1, 29, 20 and 6. The average genetic gain was increased by 10.73 cm, 0.02 mm and 0.83 mm, reaching 5.29%, 6.38% and 2.24%, respectively.

Key words: Eucalyptus urophylla, bark thickness, clone, growth traits